Refrigerating apparatus



June 6, 1944. A. c. FREIMANN I 2,350,386

REFRIGERATING APPARATUS I Filed Dec. 30, 1941 3 Sheets-Sheet l ie INVENTORQ J1me A. c. FREIMANN 2,350,886

REFRIGERATING APPARATUS Filed Dec. 50, 1941 s sneets sheet 2 June 6, 1944. A. CQFRIEIMANN 2,350,886

REFRI GERATING APPARATUS Filed Dec. 30, 1941 3 Sheets-Sheet 3 Patented June 6,

Andrew C. Freimann, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application December 30, 1941, Serial No. 424,950

.10 Claims. (01. 62-6) This invention relates to refrigerating apparatus and more particularly to an improved refrigerating system for use in conditioning the air for private homes or the like.

Notwithstanding the fact that the residential air conditioning field representsone of the largest potential markets for air conditioning apparatus, the residential air conditioning field remains substantially untouched. The problems involved in designing low cost residential air conditioning apparatus suitable for use in all types and sizes of homes, in all climates, explains to a large extent why the prior art type of residential air conditioning systems have not gone into more exten-' sive use.

It is an object of this invention to provide low pass in series.

attic space through a suitable opening, such as cost air conditioning apparatus adaptable to mass production and capable of universal application in air conditioning private homes and the like.

More particularly, it is an object of this invention to provide a ductless air conditioning system capable of efficiently conditioning 100% fresh air throughout widely varying air conditioning loads. U

A further object of this invention is to provide improved control means for use in air conditioning systems in which the air to be conditioned flows in thermal exchange with two separate evaporators.

Another object of this invention is to provide a system capable of efliciently conditioning all fresh air and having means for effectively varying the air conditioning capacit throughout a I wide range of inside and outside air temperatures.

Still another objectof this invention is to provide an improved control for' varying the ratio of sensible cooling to latent cooling.

A further object of this invention is to provide an improved means for starting and stopping the operation of a plurality of refrigerant liquefying units servinga common 'air conditioning load.

Further objects and advantages of the present invention will be apparent from: the following description, reference being had to the accompanying drawings, wherein a'preferred form of the present invention is clearly shown.

In the drawings:

Fig. l is a vertical sectional view diagrammatically showing an air conditioning system constructed in accordance with my invention installed in a private home; e a

Fig. 2 is a vertical sectional view of the apparatus showing the arrangement of the elements;

Fig. 3 is a vertical sectional view showing two self-contained air' conditioning units of' similar construction connected in tandem;

Fig. 4 is a diagrammatic view showing the various controls used.

For purposes of illustration, I have-shown my system applied to a conventional two-story dwelling l0 havingan attic space l2 in whichv the entire conditioning system is mounted. a The air conditioning apparatus comprises two self-contained air conditioning units l4 and I6 through which the air to be conditioned is adapted to Air to be conditioned enters the an attic window It. The air enters the first unit l4 through the air inlet 20 and discharges downwardly 'from the second unit. It into the second floor hallway 22 from whence a portion of the conditioned air discharges intothe-second floor bedrooms 24 and another portion of the air discharges downwardly through the stairway 26.-.

The air coming down through the stairway 26 is distributed to the first floor rooms 28 through the various doorways and openings leading from the stairway 26. Inasmuch as all of the air'which is conditioned is taken from the outside through the attic window I8, it isapparent that a corresponding amount of vitiated air must be discharged to the outside from the conditioned space. In order to allow air to discharge from the conditioned rooms, some or all of the windows are permitted to remain open. Under normal conditions, the amount of conditioned air discharged into any one room will be determined I in part by the amount that the windows in that room are open, and in part by the size of the air passageway between the hallway and that room. If necessary, booster or exhaust fans may be added to facilitate air distribution-within the house.

Referring now to Fig. 3 in which-I have shown a vertical sectional view of the units It and i6, it will be observed that the air to be conditioned enters the unit It through the inlet 20 adjacent which is provided a-filter 30. The incoming air first flows in thermal exchange relationship with a water coil 32 and thereafter flows in thermal exchange relationship with a volatile refrigerant evaporator 34, both of which. are arranged in which may be either an automatic expansion the hallway;

valve or aflned restricton. Fora completedescription of the construction of the unit 36, reference is hereby made to application 326,853 flied 'March 30, 1940. A blower unit 38. driven by a motor 39 is mouinted'in the bottom portion of the unit 14 andis adapted to discharge the air flow-'- ing over the coils 32 and 34, into a plenum chamber 46 which is removably secured to the unit is.

When maximum refrigeration capacity is required, the conditioned air flows from the plenum chamber 46' through the damper 42 into the upper compartment 44 of the self-contained unit I6, as shown by the solid line arrows in Fig. 3.

A volatile refrigerant evaporator .46 is mounted in the compartment and is adapted to further cool the airwhenever the damper 42 is open or partially open. Refrigerant is supplied to the evaporator. by means of a motor-compressorf condenser unit 4! which is similar to the unit 36.. The air leaving the evaporator 46 flows downwardly into the lower compartment 48 of the second unit l6 where it is picked up by the blower .60 and is discharged into the plenum Since the amount of refrigeration required varies from time to time, it is apparent that some means must be provided for varying the amount of. cooling which takes place. As shown in Fig. 3,

s the unit 16 is provided with a damper 68 which when open allows a portion or all of the air to bypass the evaporator 46, as shown by the dotted line arrows in Fig. 3. The dampers 42 and 58 are both operated by means of a single.

damper motor 66 which will be described more fully hereinafter. The arrangement of the damper operating mechanism is such that the damper 42 moves towards closed .position when the. damper 66 is moved toward open position. By virtue of this arrangement, it is possible to vary the amount of sensible cooling by varying the amount of air flowing in thermal exchange with the evaporator 46.

In order to'more clearly illustrate the operation of the system and the controls for the system, I have included a diagrammatic showing of the apparatus lung. 4. Referring now to Fig. 4,

it will be observed thatthe dampers 42 and 56 are both operated by means of the reciprocating bar 66 whichoperates the dampers 42 and 58 through the pin and slrt connections 6! and 63 respectively. The upper end of .the bar 60 is asmssc liquid refrigerant to the evaporator 461s controlled by means of a switch 16, which in turn is controlled by the bulb 14 through the lever 68 and the switch operating arm 18 carried thereby. The arrangement of. the arm 18 and the switch 15 is such that the'arm 18 does not open the switch 16 until the damper 42 has been moved to a position in which all or substantially all of the air by-passes the evaporator 46. A back pressure regulating valve I9 of conventional construction is provided in the suction line lead- -ing from the evaporator 46 to the unit 41 and serves to limit the suction on the evaporator so as to prevent the evaporator from becoming cold enough to freeze the condensate when some of the air is by-passed.

Reference numeral 66 designates the main power supply lines. A manually operated switch 82 is-provided in the main power supply line, as

shown, and serves as a master control switch for shutting down the entire air conditioning system. An automaticallycontrolled switch 84 is also provided for starting and stopping the operation of the. entire system. The switch 84 is controlled in response to the incoming air temperature by means of the thermostat 66 and the bellows 88. While I have shown the thermostat 86 mounted in the incoming air stream so as to is apparent that this thermostat could be located so as'to respond to the temperature of the air leaving the air conditioning apparatus. or so as .to respond to the air in the conditioned space.

The blower motors 38 and 5| are arranged in series with the switch 64, as shown. Electrical 1 energy is supplied to the motor-compressor units 64 is placed in the circuit leading to the motor ture within the conditioned space.

36 and 41 through the lines 60 and 62. A switch compressor-condenser unit 36. The switch 64 is controlled by the thermostat 66 which is preferably located so as to respond to the tempera- The thermostat 96 controls the switch 64 through the medium of the bellows 68. The thermostat 66 is so calibrated as to open the switch 84 at a lower temperature than the temperature at which the switch 161s adapted to be opened by the thermostat 14. By virtue of this arrangement,

pivotally connected .to a lever 62 which merely serves to guide the upper end of the bar 66. The

- lower end oi the bar 66 is pivotally connected to a similar lever 64. Movement is imparted to the bar through the lever 66 which lawn is actuated by thelever 68. Lever 88 is pivotally supported on the stationary element I0. For

purposes of illustration. I have shown the lever 88 operated by means of a bellows 12. The bell IOWS- 12 is connected to a thermostatic bulb 14 is preferably moimted in the. conditioned space- The refrigerant liqueiying unit 41 which supplies the first self-contained unit M will be the only unit to operate when the air conditioning load is light. The second self-contained unit l6 willnot come into operation until the demand for cooling increases beyond the point at which the unit i4 is capable of supplying the necessary amount of cooling.

The incoming fresh air will deposit moisture on the water coil 32 and the evaporator 34 under most climatic conditions. This condensate will be discharged to a drain through the condensate drain line Hill. A considerable amount or moisture will also be removed from the air by the evaporator 46. Drain line [6| has been provided for draining away the condensate removed fro the airby the evaporator 46.

- As-best shown in Fig. 4, water from any suitable source such as thecity main is supplied through the line I62. Water from the line "it flows into the water coil 31 through the line I63. Water leaving the coil 32 flows through the line I64 to the water inlet of the motor-compressorcondenser unit 36 and is used for condensing the refrigerant within the unit 36. The water thereafter leaves the unit)! through the line II! which connects to the main drain line Ill. The flow or water through the water coil I! and through'the condenser "cooling portion of the by the valve lil'l'which in turn is controlled by the condensing pressure. The valve I! is of conventional construction and is adapted to increase the flow of water as the condensing pressure increases and to decrease the flow of water liil. In most communities, the prevailing water as the condensing pressure decreases. line Hi8 provides communication between the interior of the condensing chamber and the valve temperatures are low enough so that the incoming water is'capable of removing an appreciable quantity of heat from the relatively hot outside air. Inasmuch as the condensing temperature of the refrigerating system' is considerably higher than the temperature of the air leaving the water coil '32, it is obvious that the water leaving the coil 32 ,is still effective for condenser cooling purposes.

When the motor-compressor-condenser unit 41 is in operation, condenser cooling ,water is supplied thereto through the line I09 and returns to the drain through the line II. The

flow of water to the unit 41 is controlled by the valve III which is similar in construction A small motor-compressor-condenser unit 36 is controlled While the form of embodiment of the invention as herein disclosed; constitutes a preferreda form, it is to ,be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows: 1. In combination, a'first evaporator, a second evaporator,- means'for supplying liquid refrigerant to said evaporators including refrigerant condensing means, a water coil, means for flowing air to be conditioned in thermal exchange withsaid water coil and thereafter in serial thermal exchange relation with said evaporator, means for supplying'water' to said water coil, andmeans for discharging the water leaving said water coil in thermal exchange with said condensing means, and means, responsive to the temperature of the air, for -by-passing one of said evaporators with a portion of the air.

2. In combination, a first evaporator, a secon evaporator, means for supplying liquid refrigerant to said evaporators including a plurality of refrigerant condensing means, a water coil, means for flowing air to be conditioned for an enclosure in thermal exchange with said water coil and thereafter in serial thermal exchange relation with said evaporators, means for supplying water and operation to the :valve I01 described hereinabove. The line H2 provides communication between the interior of the condensing chamber andthe valve Ill.

\ In small homes when the air conditioning load does not warrant the use of two self-contained units, as shown in this application, only one unit,

would be used. 'Thus, in a small home, either one or the other of the units H or I6 would be been demonstrated that systems of the general.

type disclosed herein surpass the prior art sys-' to said water coil, means for discharging the, water leaving said water coil in thermal exchange with one of said condensing means, and means responsive to the temperature of the air in the enclosurefor rendering another of said condensing means inoperative at light air conditioning oads.

3. Air conditioning apparatus comprising in,

combination, a first self-contained volatile refrig-' erant air conditioning unit, comprising an ev'aporator, compressor, and a condenser mounted within a cabinet, a second self-contained 'air tems in all-around performance. This is espe-.

cially true when personal comfort is taken into consideration. By virtue of the fact that the units are all of the self-contained type, the entire refrigeration circuitmay be assembled and tested by the experienced factory workers rather than by the less skilled field representatives.

In order to simplify this disclosure, all of the controls have been shown as dry bulb thermostats, whereas, it is within the purview of this invention to substitute wet bulb thermostats, effective temperature thermostats, hygrostats, or a combination of two or more of these controls for any one of the controls shown. It is also within the purview of this invention to provide inside controls which are modified in accordance with changes in the outside air conditions. Controls of this type are now well known and need no furtherdescription. Q

The same general arrangement of heat exchange coils as shown herein could also be used for heating the enclosure merely by providing conventional means, not shown, for reversing the refrigerant cycle of each refrigeration system. It is also apparent that many features of my invention are equally applicable to non-residential air conditioning systems and to various types of systerns using ducts for distributing the air.

conditioning unit comprising an evaporator, compressor and condenser mounted within a cabinet,

means for flowing air to be conditioned in thermal exchange with the evaporator of said first unit was to cool said air, means for discharging the air thus cooled into said second named cabinet, means for flowing at least a portionof the air entering said second named cabinet in thermal exchange withthe evaporator of said second unit, and means for by-passing a varying amount of air around the evaporator of said second unit, an air outlet for said second named cabinet, a plenum chamber adjacent said outlet into which all of the air is discharged, said plenum' chamber having an outlet in the bottom wall thereof through which the air is discharged downwardly into a space to be conditioned.

4. Air conditioning apparatus comprising in combination, a first volatile refrigerant air conditioning unit, comprising an evaporator, compressor, and a condenser, a second air conditioning unit comprising an evaporator, compressor and condenser, cabinet means enclosing said units, meansfor fiowi'ng air to be conditioned in" thermal exchange with the evaporator of said first unit so as to cool said air, means for flowing at least a portion of the air leaving the first evaporator in thermal exchange with the evaporatorof said second unit, means for by-passing a varying amount of air around the evaporator 4 charged downwardly 'into a space to be' con tionedr x 5. Air conditioning-apparatus comprising in combination, a first self-contained volatile re-' frigerant air conditioning unit, comprising an evaporator, compressor, and a condenser mounted within a cabinet, a -second self-contained air conditioning unit comprising-an evaporator, compressor and condenser mounted within 'a cabinet,

means for flowing air to :be conditioned in'the'rmal exchange with the evaporator of said-first unit so as .to cool said air, means for discharg= ing the air thus cooled, into said second named cabinet, means for flowing at least a portion of the air entering said "second named cabinet in asa'asee mal exchange with said secondev aporator,

" control apparatus responsive. to the temperathermal exchange with the evaporator of said second unit, and means for by-passing a varying amountof air around the evaporator of said sec-' ond unit, said cabinet having an outlet in the bottom wall thereof through which the. conditioned air is discharged downwardly into a space- .cuit means for energizing said means for supplying liquid refrigerant to said second'evaporator.

switch means in said-circuit means, an temperature responsive means controlling said damper andsaid switch meana'said air temperature responsive means being so constructed and arranged that said switch means is opened when said damper means occupies a position in which substantially all 01' the air by-passes said second named evaporator.

'7. In combination with abuilding having a room above the space to be conditioned, air conditioning apparatus disposed within said-room comprising in combination, a first evaporator, a second evaporator, refrigerant liquefying means for supplying liquid refrigerant to said first evaporator, refrigerant liquefying means for supplying liquid refrigerant to said second evaporator, means for flowing all fresh air to be conditioned in thermal exchange with said evaporators and ior discharging the air downwardly into the conditioned space,- said last named means being so ture or the air for controlling the amount of air which flows in thermal exchange with said second evaporator and'ior rendering-the meansv for supplying liquid refrigerant to said second evaporator ineflective when said first evaporator has V ample capacity to cool the air the desired amount.

-8. Incombination with an enclosure to be cooled; a first evaporator; a second evaporator;

means for supplying liquid refrigerant to'said evaporators including reirigerant condensing means; a water coil; means for flowing air, at least the greaterportion of which isi'resh air, in thermal exchange relation with said water coil and thereafter in serial thermal exchange relation with said evaporators; means for ing the air leaving said evaporator downwardly intosaid enclosure; means for supplying-water to said water coil;- means for discharging the water leaving said water coil in thermal exchange with said condensing means; and means, responsive to the temperature of the air, for by-passing one I of said evaporators with a portion of the air.

9. In combination, a first evaporator; a sec- .ond evaporator, means for supplying liquid reirigerant to said evaporators including a plurality of refrigerant condensing means, a water coll, means for flowing air to be conditioned for an enclosure in therma exchange with said water exchange with one of said condensing means,

means responsive to the temperature of the air "coilla'nd thereafter ,inserial thermal exchange relation with said evaporators, means for supplying water-to said water coil, means for discharging the water leaving said wat'ercoilin thermal in the enclosure for rendering another of said condensing means inoperative at light-air con ditioning loads, and cabinet means enclosing said evaporators, said cabiet means including a plenum chamber having an outlet for discharging the air downwardly.

' 10. In combination, a first evaporator, asecond evaporator, means for supplying liquid refrigerant to said evaporators including a plurality or refrigerant condensing means, a water coil, V

' means for flowing air to be conditioned in therconstructed and arranged that all of the air flows in thermal exchange with said first named evapmal exchange withsaid water coiland thereafter in serial thermal exchange relation with said evaporators, meansiior supplying water to said water coil, means for discharging the water leaving said water coil in thermal exchange with one of said condensing. means, and means for rendering another 01' said condensing means inoperative at light air conditioning loads, said last named means including means for by-passing one of said evaporators with at least a portion of z the air.

- ANDREW C. FREIMANN. 

